If in blood or in bone marrow:Acute myeloid leukemia (AML)Myelodysplastic Syndromes (specifically RAEB-II)

› Classic Immunophenotype:

CD34+

CD117+

HLA-DR+

CD13+

CD33+

(they may have immunophenotypic aberrancies such as gain of CD56 or CD7, etc.)

› Cartoon Image:

Click and dragfor direct comparison

› Misc:

Presence of Auer rod is diagnostic of the blasts' Myeloid origin (the only morphologic feature that could reliably distinguish a myeloblast from a lymphoblast) . Note: Other blasts (e.g. lymphoblasts) lack Auer rods